All patents, patent applications, and publications cited within this application are incorporated herein by reference to the same extent as if each individual patent, patent application, or publication was specifically and individually incorporated by reference.
The invention relates to detecting molecular binding events as well as photochemical spectral emission and/or absorption in a two-dimensionally discriminated manner such as, for example, in an array. The observation of molecular binding and affinity is a key element in biochemical and pharmaceutical research and development and analytical assays. In this field, the use of arrays is desirable in order to increase assay throughput and decrease the amount of expensive reagents consumed. Microarray technologies are commonly used in fluorescence, electrochemical, and mass spectrometry analytical instruments. However, microarray technologies based on surface plasmon resonance (SPR), which is a powerful method used for the detection of molecular affinity and binding, have developed more slowly. Array capable SPR systems are being developed that observe the angular shift in SPR upon binding using a charge couple device (CCD) camera and dual angular goniometers. In this approach, the change in reflectivity of the SPR sensor surface during a binding event is observed using the CCD output, which can be displayed as video gray level. Unfortunately, the use of dual goniometers to adjust the system to the resonance condition angle as well as to the linear portion of the SPR curve can produce a cumbersome and costly instrument. The other method of observing SPR is by wavelength absorption spectroscopy. In this approach, a molecular binding event is observed by a wavelength shift of the SPR absorption maximum. The observation of spatially discriminated or array organized binding/affinity events can be achieved by monitoring the spectra displayed at each position of a two-dimensional matrix or grid. However, there is still a need for simpler SPR sensing methods and instruments that will allow wide deployment in bioanalytics, biopharmaceutics, and proteomics with relatively compact size at low cost.